Crimping tool having an improved valve control mechanism

ABSTRACT

This invention pertains to fluid-driven crimping tool and more particularly to a valve control mechanism having a barbed and tipped shaft and locking jaws whereby the jaws permit advancing motion of the shaft but denies retraction thereof until the jaws are forced apart by engagement thereof by the shaft tip. This latter action allows a sleeve to advance between the barbs and the locking jaws, remaining in such protective position until the barbs and shaft are retracted from the locking jaws.

United States Patent 1 Rider Nov. 20, 1973 CRIMPING TOOL HAVING AN IMPROVED VALVE CONTROL MECHANISM George William Rider,1-larrisburg,

Assignee: AMP Incorporated, Harrisburg, Pa. Filed: Feb. 22, 1972 Appl. No.: 227,813

[75] inventor:

U.S. Cl. 72/412, 72/452, 72/453 Int. Cl B2ld 7/06 Field of Search 72/412, 453, 452,

References Cited UNITED STATES PATENTS 10/ 1965 Smith 72/453 6/1967 Spangler 72/453 10/1956 Van Sittert 72/453 8/1960 Demler 72/410 2/1969 Faulconer 72/453 Primary Examiner-Charles W. Lanham Assistant Examiner-Gene P. Crosby Attorney-Wil1iam J. Keating et al.

[57 ABSTRACT This invention pertains to fluid-driven crimping tool and more particularly to a valve control mechanism having a barbed and tipped shaft and locking jaws whereby the jaws permit advancing motion of the shaft but denies retraction thereof until the jaws are forced apart by engagement thereof by the shaft tip. This latter action allows a sleeve to advance between the barbs and the locking jaws, remaining in such protective position until the barbs and shaft are retracted from the locking jaws.

6 Claims, 7 Drawing Figures SHEET 2 U 4 CRIMPING TOOL HAVING AN IMPROVED VALVE CONTROL MECHANISM BACKGROUND OF THE INVENTION Portable, hand-operated tools consisting of a set of crimping dies and driven by compressed air or by simply squeezing two handles together are commonly used to crimp electrical terminal contacts onto wire. It is desirable to be able to operate such tools in two stages; the first being that where the dies are brought into partial engagement with each other whereby the uncrimped terminal contact is gently held. The operator of the tool can then more precisely insert the wire into the barrel of the terminal contact and hold it there during the second or crimping stage to insure a good mechanical and electrical crimp. Obviously the tool mechanism must be such as to allow the two separate stages. Hand powered tools accomplish this via racheting mechanism which allows the operator to advance the dies toward each other in incremental steps. An example of such is disclosed in U.S. Pat. No. 2,947,207. As noted therein, once the crimping operation is started, the handles cannot again be opened until the operation has been completed. Also, the racheting mechanism permits the operator to lay the tool down without disturbing the step or stage it might be in at that time.

Air powered tools present more difficulty in developing an actuating mechanism which allows the two or more crimping stages. One such development is disclosed in U.S. Pat. No. 3,212,316. Whereas the disclosed embodiment therein overcame such difficulties in an admirable fashion, a portion of its actuating and releasing mechanism was by necessity positioned on the outside of the tool and thusly exposed to contaminates and so forth which are capable of inducing difficult manipulation and more rarely jamming of the parts.

Accordingly the present invention provides a fluid operated crimping tool comprising crimping means for crimping terminal contacts onto wire, power means for actuating said crimping means, valve means for regulating power fluid to said power means, and valve control means for controlling said valve means.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective of a crimping tool embodying the principles of the present invention;

FIG. 2 is a longitudinal section view showing the internal mechanisms of the crimping tool of FIG. 1, the parts being shown in their static positions;

FIG. 3 is a plan view of the valve control mechanism of FIG. 2; and

FIGS. 4-7 are longitudinal sectional views of the valve control mechanism of FIG. 2 showing the operational positions thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows crimping tool 10. The basic components thereof are handle 12, air passageway housing 14 which is integral with handle 12 and a power unit assembly 16. A pair of crimping dies 20 project from the frontal opening of assembly 16. Air with which tool .10 is powered is supplied via air hose 22 and fitting 24.

Referring now to FIG. 2, tool is shown in crosssection to show the several working members and to illustrate the inter-relationship thereof.

Handle 12 contains 'abore 26 continuous from its front portion 28 (toward the left of the Figure) to its back portion 30. About midway through, the diameter at bore 26 changes to define an inclined shoulder 32 facing the front portion 28.

Housed within bore 26 to the left of shoulder 32; i.e., in front portion 28, is valve control mechanism 34. To the right of shoulder 32; i.e., in back portion 30, is valve assembly 36 which includes a cylinder 38 fixed within bore 26 by suitable fastening means such as machine screws (not shown). A piston rod 40 having two spaced apart pistons 42 and 44 fixed thereon, is slidably mounted in cylinder 38, the two pistons defining chamber 45 thereinbetween. Each piston is fitted with an O- ring 46 to provide seals between the piston and cylinder wall 48. I

The left end of rod 40 extends to and is fixed to valve control mechanism 34 via companion threads 50. The right end of rod 40 extends into compression spring 52 which abuts piston 44 on one end and backing plate 54 on the other. Backing plate 54 is fixed to handle 12 and power unit assembly 16 via machine bolts 56. A small hole 58 is provided in plate 54 adjacent spring 52.

Two ports 60 and 62, located in wall 48 of cylinder 38 provide communication between chamber 45 and a second chamber 66 positioned in power unit assembly 16 via passageways 68 and 70 which are positioned in housing 14, and by tubes 72 and 74 which are pressfitted into aligned passageways 68a and 70a located in power unit assembly 16 and extend up into aforementioned passageways 68, 70.

Passageway 70 passes through by-pass plug 76 which is positioned in recess 77 in housing 14.

O-rings 78 are provided around tubes 72, 74 to seal passageways 68, 70. Bushings 80, pressed into counterbores 82 of passageways 68, 7 0, confine O-rings 78 as shown.

O-rings 84, positioned around cylinder 38 and adjacent ports 60 and 62 isolate those ports from bore 26 and from port 86, located in cylinder 38, which connects air hose 22 to chamber 45 via passageway 88 which is positioned in housing 14. The horizontal portion of passageway 88 includes an annular groove 90 in by-pass plug 76. The lower half of the vertical portion of passageway 88 is sealed by plug 92 which is pressed therein.

Power unit assembly 16 includes a housing 18 which is a cast and machined part. The rear portion of the housing, herein designated at 18a, includes aforementioned chamber 66 which is defined by walls and end plates 102, 104. The end plates are secured to the walls via machine bolts (not shown). A piston 106, positioned in chamber 66, is attached to piston rod 108 which passes through end plate 102 and is attached to cam 110 via pin 112. O-rings 114 on plates 102, 104 seal chamber 66 and O-rings 116 on piston 106 provide a seal between the piston and cylinder wall 118. A bushing 120, pressed into a stepped bore '122 in plate 102, and an O-ring 124 between the bushing and rod 108 provide a suitable seal thereinbetween while allowing reciprocal motion of the rod.

Power unit assembly 16 is attached to handle 12 housing 14 via machine screws one of which is shown at 126.

The front portion of housing 18, herein designated at 18b, consists of two spaced apart, parallel side plates (see FIG. 1). The two plates 130 define a space 131 thereinbetween and a frontal opening 132. A recess 133 is bored out on the inside of each plate 130 to increase the area of space 131 and thereby accommodate the reciprocal movement of cam 1 therein. Two covers 134, located on the top and bottom of plates 130, and hinged thereto via pins 136, are provided to allow ready access to space 131.

Rocker arms 138, integral with crimping dies (see FIG. 1), positioned partly within space 131 and projecting outwardly through opening 132, are pivotally mounted to side plates 130 via pins 140 extending through appropriate holes (not shown) located in the arms and in the plates and through a pair of spacers 142, each of which is interposed between arms 138 and a plate 130. Referring to FIG. 1, such spacers, although not called out, can be seen. Removable pins 143, passing through covers 134 and spacers 142 hold the covers in place.

The rear end 144 of each rocker arm 138 contains a roller 146 rotatably mounted in a slot (not shown) via pins 148; such rollers engage cam 110. As the cam moves forward, arms 138 are pivoted about pins 140 so that crimping dies 20 close in toward each other. Particular attention is directed toward the parabolic shape of cam 110. Such shape will cause crimping dies 20 to approach each other rapidly at first and then more slowly as cam 110 advances further forward.

A pair of springs 150, attached at one end to covers 134 via housing 152, bear on each rear end 144 of each rocker arm 138 to bias crimping dies 20 open as cam 110 is withdrawn from engagement with rollers 146.

In describing valve control mechanism 34, reference is directed to FIGS. 3 and 4 as well as to FIG. 2. The mechanism is housed in actuator 170 which is movably confined within handle 12 (see FIGQ3) via pin 172 which extends through lateral slots 174 in actuator 170 and holes 176 in handle 12. Actuator 170, cylindrical in shape, contains, besides lateral slots 174, a large longitudinal slot 176 and a centrally positioned, threaded passageway 178 longitudinally extending from slot 176 to semi-elliptical, concave end 180. At the other end, actuator 170 contains a recess 182 adapted to receive a threaded bushing 184 which in turn threadedly receives piston rod 40.

In addition to holding actuator 170 in handle 12, pin 172 retains locking jaws 186, 188 in a stationary position within slot 176 relative to actuator 170. The base of locking jaw 186 consists of two spaced apart inwardly projecting flanges 190 which receive thereinbetween a single flange 192 attached to and projecting inwardly from locking jaw 188. I-Ioles 194 located in flanges 190, 192 receive afore-mentioned pin 172 around which jaws 186, 188 pivot.

The remaining portions of locking jaws 186, 188 are identical, one being the mirror image of the other. At the top of each is an inwardly projecting flange or finger 196-having a beveled surface 198. Directly below finger 196 is a pair of notches 200, one on each side of locking jaws 186, 188 and adapted to receive an elastomer ring 202 which biases fingers 196 and jaws 186, 188 together. Positioned between notches 200 and flanges 190, 192 are inwardly projecting steps 204, each having a beveled surface 206.

A sleeve 208, having a laterally extending rim 210 on one end, abuts fingers 196 at its other end as seen in FIGS. 2 and 3. The sleeve is longitudinally bored from end-to-end to receive shaft 212. A slot 214 in sleeve 208, a hole 215 in shaft 212 and pin 216 cooperate to limti reciprocal movement of sleeve 208 on the shaft. A coil spring 220, positioned about shaft 212, is confined between rim 210 of sleeve 208 and an end of slot 176 as seen in FIG. 2.

Shaft 212 has a pointed tip 222 on one end. Adjacent to tip 222 are three barbs designated at 224a, 224b and 224c. Each barb, beveled at its forward end, is flat at its other end. Shaft 212 is attached to actuator 170 via threaded end 226 which is slotted at 228 to receive a screw driver for adjusting and removal of the shaft.

OPERATION OF THE PREFERRED EMBODIMENT The operation of the preferred embodiment will now be described using FIGS. 5, 6 and 7 as well as FIGS. 1, 2 and 3.

FIGS. 2 and 3 illustrate the positioning of the several parts in tool 10 before crimping of a terminal contact onto an electrical lead begins. Note particularly the position of pistons 42, 44 in valve assembly 36 relative to ports 60, 62. This positioning permits air, entering chamber 45 via passageway 88 and air hose 22, to enter power unit chamber 66 and hold piston 106 back against end plate 104. Crimping dies 20 are open as seen in FIG. 1. Also note the positioning of barbs 224 in FIGS. 2 and 3 relative to locking jaws 186, 188; i.e., fingers 196 are in front of barb 244a.

In FIG. 5, actuator 170 has been pushed inwardly in the direction as shown by the arrow. As the actuator moved, the beveled portion of barb 224a cammed locking jaws 186, 188 outwardly just enough to allow the barb to pass fingers 196 at which time elastomer ring 202 urged the fingers and locking jaws back inwardly, locking the barb in behind the fingers. Because the bottom of fingers 196 and the back end of the barb are flat surfaces, actuator 170 cannot be retracted. The forward motion of actuator 170 caused piston rod 40 to move pistons 42, 44 (not shown) toward backing plate 54 a distance sufficient to allow O-ring 46 on piston 42 to move just past port and piston 44 to slightly open port 62 to chamber 66. This permits air to enter chamber 66 between plate 104 and piston 106, driving piston 106, rod 108, and cam slowly forward. It also allows escape of pressure between piston 106 and plate 102 via passage 68 and bore 26. Rollers 146, riding over the surface of the cam, pivots rocker arms 138 about pins so that crimping dies 20 move in toward each other. The pressure on piston 106 is enough to close the crimping jaws and hold a workpiece placed thereinbetween but is not enough to apply deforming force thereto. Further, spring 52 at the right end of bore 26 has been somewhat compressed between advancing piston 44 and back plate 54.

FIG. 6 shows that actuator has been additionally advanced to where barb 224b had moved in past fingers 196 in the same manner as had barb 224a, and the actuator is now locked in a second position. This advancement also pushed piston 42 past port 60 and piston 44 past port 62 such that the total air pressure from passageway 88 flows in behind piston 10.6 driving it completely forward. This causes further pivoting of arms 138 such that crimping dies 20 forcefully crimp the workpiece. Again actuator 170 is locked in place and release or pressure thereon will not permit retraction thereof.

FIG. 7 illustrates the method of releasing barbs 224 from cooperation with fingers 196 such that the mecha nisms of tool can be turned to the static or open position seen in FIG. 2.

In FIG. 7, actuator 170 is further depressed to where tip 222 on shaft 212 engages and cams steps 204. Locking jaws 186, 188 pivot outwardly as seen in FIG. 7 far enough to allow spring 220 to slide sleeve 208 down shaft 212 in between fingers 196 and over barbs 224. Then, as pressure is released from actuator 170, spring 52, by now fully 200 compressed, pushes back on the valve assembly and valve control mechanism. The barbs 224 are able to withdraw from fingers 196 as such are sheathed by the sleeve and shaft 212 can be retracted from jaws 186, 188. Note that slot 214 in sleeve 208 allows the sleeve to remain in protective cover until the barbs 224 are back away from fingers 196. As the shaft is further withdrawn, the limit of slot 214 is reached and the sleeve is pulled back along with the rest of shaft 212. After the sleeve and shaft have been withdrawn, locking jaws 186, 188 under the force of elastomer ring 202, pivot back into the closed position seen in FIG. 2. At the same time as this is happening, pistons 42, 44 are moving back to where port 62 is closed off and port 60 is reopened so that the air pressure is diverted via port 60 to chamber 66 and in between plate 102 and piston 106, driving the piston, rod 108, and cam 1 l0 backwardly. Springs 150 pushing on ends 144 of arms 138 rotate the arms about pin 140 and open crimping dies 20, releasing the now crimped workpiece therefrom. Air trapped between piston 106 and end plate 104 escapes via passageway 70, port 62 and hole 58. At this point crimping tool 10 is now in the position seen in FIG. 1 and 2.

The salient advantage of the invention is the valve control mechanism with which the operator can, at any time during the crimping operation, lay the tool aside, its parts locked in place, without undoing the previous steps. Thus the operatorcan at any time have use of both hands with which to adjust the terminal and the wire onto which it is to be crimped. 4

Another feature of the invention is the parabolicshaped cam which provides changing acceleration of the dies as they approach one another.

Yet another feature of the invention is the integral construction of the handle-air passageway housing group and the power unit assembly.

Still another novel feature of the invention is the ready accessibility to the dies-rocker arms and the changing thereof.

Although the invention has been described with reference to the embodiment illustrated, it will be appreciated by those skilled in the art that additions, modifications, substitutions, deletions, and other changes not specifically described may be made which fall within the spirit of the invention as defined in the following claims.

I claim:

1. A fluid operated crimping tool, which comprises:

a. moveable crimping means for crimpingterminal contacts onto wires;

b. fluid operated power means for moving said crimping means;

c. valve means for regulating power fluid to actuate said power means; and

d. valve control means for controlling said valve means, said valve control means including; i. a pair of locking jaws pivotally connected to each other at a first end, each jaw having an inwardly projecting finger at a second end and an inwardly facing beveled step between said first and second ends; and

2. a shaft having a tipped end and a plurality of barbs adjacent said tipped end, said shaft operable to enter between said pair of jaws, said bars in cooperation with said fingers operable to prevent withdrawal of said shaft from said pair of jaws, and said tipped end adapted to engage said inwardly facing beveled steps thereby forcing said jaws to open.

2. The crimping tool of claim 1 wherein said valve control means include a sleeve slidably mounted on said shaft and operable to slide in between said barbs and said fingers at such times as said tipped end forces said jaws to open thereby allowing said shaft to withdraw from said jaws.

3. The crimping tool of claim 2 wherein said valve control means includes spring means to bias said sleeve in between said barbs and said fingers.

4. In a fluid operated crimping tool of the type having crimping dies, piston and piston rod operable to move the dies and valve means operable to direct fluid to and away from a chamber containing the piston, the improvement comprising:

A. a valve control assembly operable to control said valve means, said assembly including a. a pair of locking jaws pivotally connected to each other at one end, each jaw having an inwardly projecting finger at another end and an inwardly facing step between said ends;

b. a shaft having a tipped end and at least one barb adjacent said tipped end, said shaft adapted to be inserted in between said fingers on said jaws wherein said barb and said fingers cooperate to prevent withdrawal of said shaft from said jaws until said tipped end engages said step on said jaws causing said jaws to open;

c. a sleeve slidably mounted on said shaft and operable to slide between said barb and said fingers as said tipped end causes said jaws to open thereby allowing said shaft to be retracted from said jaws;

d. actuating means connected to said shaft on one end and to said valve means at another end; and

e. a coil spring slidably mounted on said shaft adjacent said sleeve and operable to urge said sleeve in between said barb and said fingers.

5. A device having a releasing mechanism operable after completion of incremental advances, which comprises:

a. a pair of jaws pivotally joined at a first end, each jaw having an inwardly extending flange at a second end and an inwardly facing step between said first and second ends;

b. a shaft having a tipped end and at least one barb adjacent said tipped end, said shaft adapted to be inserted into said jaws between said fingers whereby said barb and said fingers cooperate to deny withdrawal of said shaft from said jaws, and said tipped end operable to engage and pry said inwardly facing steps away from each other thereby opening said jaws;

. a sleeve slidably mounted on said shaft and operable to slide over said barb and between said shaft and said fingers upon said tipped end causing the opening of said jaws whereby said shaft can be retracted from said jaws; and

d. spring means operable to urge said sleeve over said barb and between said shaft and said fingers.

6. A fluid operated crimping tool, which comprises:

a. movable crimping means for crimping deformable objects onto other objects;

b. fluid operated power means for moving said crimping means;

c. valve means for regulating fluid to said power means, said fluid adapted to operate said power means; and

cl. valve control means for controlling said valve means, said valve control means including, two jaws pivotally connected to each other at one end, each jaw having an inwardly extending finger at another end and an inwardly facing step between said ends,

a shaft adapted to be pushed in between said jaws, said shaft having at least one barb thereon, said barb in cooperation with said finger operable to prevent retraction of said shaft from said jaws, said shaft further having a tipped end thereon operable to cam said steps thereby causing said jaws to open,

a spring bias sleeve slidably mounted on said shaft and operable to slide over said barb and in between said shaft and said fingers as said jaws open in response to said tipped end camming said steps thereby permitting said shaft to be retracted from said jaws. 

1. A fluid operated crimping tool, which comprises: a. moveable crimping means for crimping terminal contacts onto wires; b. fluid operated power means for moving said crimping means; c. valve means for regulating power fluid to actuate said power means; and d. valve control means for controlling said valve means, said valve control means including;
 1. a pair of locking jaws pivotally connected to each other at a first end, each jaw having an inwardly projecting finger at a second end and an inwardly facing beveled step between said first and second ends; and
 2. a shaft having a tipped end and a plurality of barbs adjacent said tipped end, said shaft operable to enter between said pair of jaws, said bars in cooperation with said fingers operable to prevent withdrawal of said shaft from said pair of jaws, and said tipped end adapted to engage said inwardly facing beveled steps thereby forcing said jaws to open.
 2. a shaft having a tipped end and a plurality of barbs adjacent said tipped end, said shaft operable to enter between said pair of jaws, said bars in cooperation with said fingers operable to prevent withdrawal of said shaft from said pair of jaws, and said tipped end adapted to engage said inwardly facing beveled steps thereby forcing said jaws to open.
 2. The crimping tool of claim 1 wherein said valve control means include a sleeve slidably mounted on said shaft and operable to slide in between said barbs and said fingers at such times as said tipped end forces said jaws to open thereby allowing said shaft to withdraw from said jaws.
 3. The crimping tool of claim 2 wherein said valve control means includes spring means to bias said sleeve in between said barbs and said fingers.
 4. In a fluid operated crimping tool of the type having crimping dies, piston and piston rod operable to move the dies and valve means operable to direct fluid to and away from a chamber containing the piston, the improvement comprising: A. a valve control assembly operable to control said valve means, said assembly including a. a pair of locking jaws pivotally connected to each other at one end, each jaw having an inwardly projecting finger at another end and an inwardly facing step between said ends; b. a shaft having a tipped end and at least one barb adjacent said tipped end, said shaft adapted to be inserted in between said fingers on said jaws wherein said barb and said fingers cooperate to prevent withdrawal of said shaft from said jaws until said tipped end engages said step on said jaws causing said jaws to open; c. a sleeve slidably mounted on said shaft and operable to slide between said barb and said fingers as said tipped end causes said jaws to open thereby allowing said shaft to be retracted from said jaws; d. actuating means connected to said shaft on one end and to said valve means at another end; and e. a coil spring slidably mounted on said shaft adjacent said sleeve and operable to urge said sleeve in between said barb and said fingers.
 5. A device having a releasing mechanism operable after completion of incremental advances, which comprises: a. a pair of jaws pivotally joined at a first end, each jaw having an inwardly extending flange at a second end and an inwardly facing step between said first and second ends; b. a shaft having a tipped end and at least one barb adjacent said tipped end, said shaft adapted to be inserted into said jaws between said fingers whereby said barb and said fingers cooperate to deny withdrawal of said shaft from said jaws, and said tipped end operable to engage and pry said inwardly facing steps away from each other thereby opening said jaws; c. a sleeve slidably mounted on said shaft and operable to slide over said barb and between said shaft and said fingers upon said tipped end causing the opening of said jaws whereby said shaft can be retracted from said jaws; and d. spring means operable to urge said sleeve over said barb and between said shaft and said fingers.
 6. A fluid operated crimping tool, which comprises: a. movable crimping means for crimping deformable objects onto other objects; b. fluid operated power means for moving said crimping means; c. valve means for regulating fluid to said power means, said fluid adapted to operate said power means; and d. valve control means for controlling said valve means, said valve control means including, two jaws pivotally connected to each other at one end, each jaw having an inwardly extending finger at another end and an inwardly facing step between said ends, a shaft adapted to be pushed in between said jaws, said shaft having at least one barb thereon, said barb in cooperation with said finger operable to prevent retraction of said shaft from said jaws, said shaft further having a tipped end thereon operable to cam said steps thereby causing said jaws to open, a spring bias sleeve slidably mounted on said shaft and operable to slide over said barb and in between said shaft and said fingers as said jaws open in response to said tipped end camming said steps thereby permitting said shaft to be retracted from said jaws. 